2011 Ohio-Michigan Silage Test
Rich Minyo, Peter Thomison, and William Widdicombe
In 2011, we conducted a joint trial with Michigan State University (MSU) adding one Ohio silage location to Michigan's two southern (Zone 1) silage locations. The Ohio test site was located in our Northwest Region at Hoytville (Wood County) The two MSU sites are located in Branch and Lenawee counties which are on the Ohio/Michigan state line. The test results from the three locations are treated as one region. The plots were planted with 4 row air type planters and maintained by each respective state utilizing standard production practices. The center 2 rows were harvested with MSU's self propelled forage harvester. Silage tests were harvested uniformly as close to half milk line as possible. Near Infrared Reflectance (NIR) Quality Analysis was performed by MSU using their current procedures. Silage results present the percent dry matter of each hybrid plus green weight and dry weight as tons per acre. Other data presented include percent stand, the percentage of in vitro digestible dry matter, acid detergent fiber, neutral detergent fiber, crude protein and starch. Milk production in pounds per ton and pounds per acre are estimated using MILK2006.
Testing procedures (randomization, replication, planting rates, etc.) for silage evaluation are the same as those utilized for the grain trials. Plots were four rows wide, and the center two rows were harvested for yield and quality.
Silage plots were harvested with a two-row self-propelled
forage harvester. Electronic scales mounted on
the chopper measured plot weights. Total plot weight is
used to calculate green tons per acre (GT/A). Sub samples
were collected (fodder plus grain), weighed, oven dried
until weight loss was zero, then weighed again to determine
the percent dry matter (%DM). Dry tons per acre (DT/A)
is calculated using GT/A multiplied by %DM. The samples
were ground using a 1.0 mm screen before conducting
quality analysis using NIR (near infrared reflectance).
All silage tables provide silage quality data as determined by NIR analysis on freshly dried samples. Data is provided for individual locations and also averaged over multiple locations. Near infrared spectral analysis involves irradiating the ground sample with light in the near infrared spectrum (1,100 to 2,500 nm). The illuminated sample absorbs light proportional to specific chemical and physical properties. The reflected energy is measured and was correlated statistically with the 2011 near infrared spectroscopy (NIRS) equation established for forage quality levels. Results of the six quality traits analyzed are presented in the quality tables. The six quality traits are:
Silage quality traits are reported on a dry matter basis (100 percent DM). Quality traits in these tables are intended for use in hybrid selection only. Analysis for the balancing of feed rations should be analyzed from hybrids grown on each individual farm.
An updated calculation using the MILK2006 equation (UW-Madison Dairy Science Department) was used to estimates MK/T (milk per ton) and MK/A (milk per acre). MILK2006 estimates the dry matter intake using the NDF and CWD (cell wall digestibility) parameters of the sample. The updated equation utilizes CP, fat, and sugar as well as the organic acid fractions along with their total-tract digestibility coefficients to estimate energy. Whole plant dry matter was calculated to 34% for all hybrids and digestibility coefficients used for the fat and sugars as well as the organic acid fractions were held constant. MILK2006 also assumes the weight of the cow is 1,350 lbs. and that it consumes a 30 percent NDF diet. Using National Research Council (NRC, 2001) energy requirements, the estimated intake of energy from corn silage is converted to milk per ton. Milk per acre is then calculated using the estimated values for milk per ton and dry matter yield per acre. For more information on the utility of MILK2006 please see: http://www.uwex.edu/ces/crops/uwforage/Milk2006silage.html